This invention relates generally to a relatively simple and easy-to-use riser lock unit for installation onto an elevated riser of a pop-up type irrigation sprinkler to retain the riser in the elevated position during service and/or replacement of a spray nozzle mounted thereon. Following appropriate nozzle reinstallation onto the riser, the lock unit is quickly and easily removed from the riser to permit normal spring-loaded retraction into an underlying sprinkler housing.
Pop-up type irrigation sprinklers are well known in the art, wherein a sprinkler housing is adapted for connection to an irrigation water supply. When the water supply is turned on, water under pressure flows into and through the sprinkler housing, and further upwardly through a tubular pop-up riser to a spray nozzle mounted at the riser upper end. The water pressure causes the riser to move against a retraction spring from a normal retracted position concealed substantially within the sprinkler housing to an elevated position projecting upwardly from the sprinkler housing. In this elevated position, the spray nozzle is disposed generally above surrounding vegetation and the like and functions to distribute the irrigation water over a surrounding terrain area with a selected spray pattern. When the water supply is subsequently turned off, the retraction spring returns the riser back to the normal retracted position disposed substantially within the sprinkler housing.
In normal operation, the spray nozzle mounted at the upper end of the riser may require periodic cleaning to remove undesired grit or other particulate obstructions which have become trapped therein, resulting in interference with or obstruction of the desired pattern of irrigation water spray discharged therefrom. Alternately, it may be necessary or desirable to replace an existing spray nozzle with an alternate spray nozzle designed to discharge irrigation water with a different spray pattern. In either case, it has been necessary for service personnel to manually grasp a low profile flange at the top of the spray nozzle exposed generally at the top of the sprinkler housing, when the water supply is turned off, and to manually lift and hold the riser against the retraction spring downforce, while simultaneously removing and/or replacing the spray nozzle. Such manipulation of the riser and spray nozzle can be quite difficult. Moreover, cleaning of a removed spray nozzle normally requires both hands, whereby the riser must be released during such procedure, and then regrasped and pulled back toward the elevated position before remounting a cleaned spray nozzle thereon.
There exists, therefore, a significant need for a simple and easy-to-use riser lock unit or fixture for mounting onto an elevated riser of a irrigation sprinkler, for mechanically retaining and maintaining the riser in the elevated position to permit quick and easy access to a riser-mounted spray nozzle for suitable maintenance and/or replacement. The present invention fulfills these needs and provides further related advantages.